// 通用样式
*{
  margin:0;
  padding:0;
}
html,
body,
#root{
  height:100%;
}
a{
  color:#333;
  text-decoration:none;
}
.spinner{
  border:4px solid rgba(255, 255, 255, 0.5);
  border-radius:50%;
  border-top-color:rgba(0, 0, 0, 0.3);
  transition-delay:250ms;
  position:absolute;
  left:25%;
  right:25%;
  top:25%;
  bottom:25%;
  margin:auto;
  width:32px;
  height:32px;
  animation:rotate-spinner 1s linear;
  animation-iteration-count:infinite;
}
@keyframes rotate-spinner{
  100%{
    transform:rotate(360deg);
  }
}
